Arid Zone Journal of Engineering, Technology and Environment (AZOJETE)
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Quality Characteristics of Lamba as Affected by Different Cereal and Legume Flour Blends
Get PDFTraditional foods are preserved cultural heritage passed down from generation to generation, and their recipes have remained unchanged for centuries. Lamba is a traditional food processed from the blends of maize, cowpea and karkashi (false sesame leaves). However, if prepared and consumed, lamba enriched with different flour blends will provide a healthy alternative to consumers. This study aimed to prepare and evaluate the quality of lamba produced from wheat – cowpea – karkashi (Wck), wheat– soybeans – karkashi (Wsk) and lastly, wheat –bambara groundnut– karkashi (wbk) flour blends in three different ratios, (70:20:10, 60:30:10 and 50:40:10) where maize-cowpea -karkashi (Mck) is the control (in the ratio of 70:20:10). The total of ten (10) different samples were produced including the control. Proximate composition, functional and microbial content of lamba samples were determined. The proximate composition of the lamba such as moisture, protein, fat, ash, crude fiber and carbohydrate ranged from .40 –9.92%, 7.92 – 15.39%, 3.82 – 9.25%, 2.78 – 3.48%, 2.03 – 3.55% and 64.24 – 73.55% respectively. Subsequently, there are significant differences (p≤0.05) between the functional properties such as wettability, bulk density, water absorption capacity and swelling index of the flour blends which ranged from 50.13 – 68.18 sec, 0.60 – 0.76 g/ml, 58.93 – 105.58 %, 1.36 – 2.15% respectively. Also, wettability, bulk density, water absorption capacity and swelling index have been determined and the control sample (Mck) had the highest. Similarly, microbiological analysis shows the bacterial load ranged from 4.9 ×104 – 8.1 × 104 cfu/g and sample Wbk 3 had the highest Mck (control sample) had the lowest. However, there was no significant difference between all the remaining samples. additionally, fungal load ranged from 1.6 × 10 5 – 4.4 × 105 cfu/g and sample Wsk 2 had the highest fungal count while sample Wbk 3 had the lowest. Sensory attributes of lamba were evaluated ranging from 5.09 – 6.13 for texture, 5.01– 6.38 for aroma, 4.92 – 7.98 for taste, 4.61 – 6.08 for colour and 5.18 – 8.49 for overall acceptability. The study shows that lamba produced from different ratio of wheat, soybean, cowpea, bambara groundnut and karkashi contains higher nutritive value. It is also acceptable as compared to lamba produced from maize, cowpea and karkashi. Therefore, this study recommends that the blend of 60% wheat, 30% soybeans and 10% karkashi (Wsk 2) can be used for the production of lamba with the desired nutritional and sensory quality as alternative to soybean
A Systematic Review of Value Engineering Practices in Construction Projects in Tanzania
No full textValue engineering (VE) has become a vital component of construction management, improving project outcomes in terms of cost, time, quality, safety, environmental performance, stakeholder satisfaction and social value. This study systematically reviews VE practices to assess their applications, benefits, barriers, and future research directions, with emphasis on Tanzania’s construction industry. A structured search of Google Scholar and Semantic Scholar retrieved peer reviewed publications from 2005 to 2025, yielding about 70 sources, of which 32 highly relevant studies were analyzed in depth. The review shows that VE delivers quantitative benefits such as cost and time reduction, alongside qualitative gains including enhanced construction quality and better management through multidisciplinary teamwork. However, its adoption in Tanzania remains limited due to inadequate awareness, cost-driven procurement systems, and a shortage of trained VE professionals. This study further identifies critical success factors (CSFs) across VE phases, including effective project information preparation, cost-based comparison of design alternatives, systematic planning and implementation, and strong stakeholders support. It concludes by recommending the development of localized VE guidelines and increased awareness among clients and top management to enhance decision-making and promote wider VE adoption in Tanzania
Effect of Moisture Content and Oil Palm Varieties on The Coefficient of Sliding Friction of Kernel and Shell on Fibre Material (Rug Canvas)
No full textThe effect of moisture content of two varieties of palm kernel and shell on the coefficient of sliding friction of the two faces (face A and face B) of a fibre material was determined. Standard procedures were used to determine the moisture content for both kernel and shell of tenera and dura varieties. The results show that the moisture content of dura and tenera varieties were 17.4 and 18.2% which were individually adjusted to 9, 13 and 17% by adding 76.3, 39.8 and 3.3 g; and 82.3, 46.4 and 10.6 g distilled water respectively. The angle of repose apparatus was used to determine the coefficient of sliding friction of palm kernel and shell of dura and tenera varieties on the two faces of fibre material. It was observed that the average values of dura palm kernel and palm shell coefficient of sliding friction on the two faces of fibre material ranged from 0.458-0.777 for 9% moisture content; 0.510-0.690 for 13% moisture content and 0.532-0.777 for 17% moisture content. Additionally, the average values of tenera kernel and shell coefficient of sliding friction on the two faces of fibre material ranged from 0.546 - 0.864 for 9% moisture content; 0.506-0.953 for 13% moisture content; and 0.537-0.927 for 17% moisture content. Therefore, we observed that the moisture content of either dura palm kernel or dura palm shell had significant effect (p<0.05) on the coefficient of sliding friction on face A and face B of the fibre while the moisture content of either tenera palm kernel or tenera palm shell had insignificant effect (p>0.05) on the coefficient of sliding friction on face A and face B of the fibre. The coefficient of sliding friction on fibre was affected by the moisture content of dura variety but not of that tenera variety
Performance Evaluation of Solar Panel with Reflector Using Nano Fluids
Get PDFThis research evaluated the performance of solar panel with reflector using Nano Fluids in Kano State, Nigeria. An experimental setup was designed, consisting of a solar panel without modification PWM, solar panel with reflectors PWR, solar panel with reflectors and a water-cooling system (PWRC). The experiments were conducted at the optimum tilt angle of 12o in Kano State. Additionally, models were developed using SolidWorks of PWR and PWRC to simulate the thermal behavior of the panel with different coolant types, including water, ethylene glycol, and urea liquid using ANSYS. The results indicate that ethylene glycol exhibited the lowest rate of increase in the panel's surface temperature (ST), followed by urea liquid and then water. For an initial surface temperature (ST) of 27.5°C, 64.2°C, and 46.1°C, the panel using ethylene glycol experienced temperature increases of 22.072°C, 74.184°C, and 33.951°C, respectively, over a duration of 50 minutes. In the case of water, the panel's ST rose by 33.155°C, 80.388°C, and 59.698°C under the same initial ST conditions. Similarly, the panel using urea liquid witnessed surface temperature increases of 24.648°C, 74.282°C, and 35.498°C for the respective initial ST values of 27.5°C, 64.2°C, and 46.1°
Performance of Concrete Using Metakaolin as Cement Partial Replacement Material
Get PDFConcrete, due to its versatility and ready availability, continues to be of great importance around the world, and with the increasing need for shelter, the force pulled by construction activity brought about the high demand for construction materials and a devastating effect on the environment due to the activities from the raw materials needed in the production of cement and concrete. This research investigates the effect of metakaolin as a partial replacement of cement for concrete production. Cement was partially replaced by metakaolin at 5%, 10%, 15%, 20%, 25% and 30%. A constant water/binder ratio of 0.50 was used. The parameters investigated include the chemical composition of metakaolin, setting time, workability, density, compressive strength, split tensile strength, and flexural strength. The results showed that metakaolin is a good pozzolan with combined SiO2, Al2O3 and Fe2O3 to equal 92.89%. The results from the test show that the inclusion of metakaolin increased the setting time of cement metakaolin paste and resulted in the workability reduction of concrete as partial cement replacement with metakaolin increases. This research reveals that partial cement replacement with 0% and 10% MTK in concrete both gave an average compressive strength of 28.9 N/mm2, at 28 days. Meanwhile, the highest value for compressive strength obtained at 90 days is 34.8 N/mm2, which was at 10% replacement with MTK. The result shows that metakaolin (MTK) has a pozzolanic effect, considering the strength activity index and improved compressive strength, split tensile strength and flexural strength of concrete. The optimum cement replacement was 10% metakaolin, which performed better than the control concrete. At later stages of curing, 15% also shows promising results. When metakaolin is calcined, it is expected to undergo pozzolanic reactions with cement hydrates, forming secondary Calcium Silicate Hydrate (C–S–H), which aids strength development. It can be concluded that metakaolin is a suitable material for partial replacement of cement up to 10%. Thus, using MTK as a partial replacement for cement in concrete at a lower replacement volume will reduce cement usage, production costs, and environmental pollution from cement production
Retrofit Design of Heat Exchanger Networks for Kaduna Refinery’s Vacuum Distillation Unit
Get PDFEffective Heat Exchanger Network (HEN) design is pivotal for improving energy efficiency and realizing substantial cost savings in chemical and petrochemical sectors. While contemporary refineries reap the benefits of economical HEN designs, there is an urgent need to enhance the utility and cost-saving features of aging refineries. These older facilities often suffer from suboptimal designs, characterized by high energy requirements and limited cost savings. To address this issue, a thorough analysis of HEN design and retrofit options is essential. The pinch design approach standout as a preferred tool for retrofitting HENs due to its physical insight and ease of application. In this study, based on pinch technology (PT), various retrofit design scenarios (re-sequencing, addition of heat exchangers, and area addition) were explored for improving the HENs of the refinery section’s vacuum distillation unit (VDU). The study revealed that the base case design achieved a Total Annual Cost (TAC) of 439.5/year, 33,810 respectively. These retrofit strategies are exceptional in reducing utility demand and improving operating cost savings. However, they required a substantial capital expenditure of 3,191, and $167,100 respectively, with payback periods of 3.9, 4.3, and 4.9 years respectively. Therefore, it is critical to explore additional retrofit possibilities to further optimize cost savings
Response Surface Modeling of Soil Moisture Content Under Different Tillage Conditions
No full textThis study investigates the impact of three key factors - irrigation deficit percentage, NPK application rate, and tillage - on soil moisture content, a crucial parameter in agricultural productivity. To achieve this, a field experiment was conducted at Nnamdi Azikiwe University's Department of Agricultural and Bioresources Engineering Experimental Site/Farm Workshop, Awka. The experiment utilized a central composite design in response surface methodology, incorporating three factors: irrigation deficit percentage, NPK application rate, and tillage. This design enabled the researchers to examine the individual and interactive effects of these factors on soil moisture content. The results of the study revealed that the model was highly significant, with an R-squared value of 0.9084. This indicates that approximately 91% of the variation in soil moisture content could be explained by the model. Furthermore, the analysis showed that irrigation deficit percentage, NPK application rate, and tillage were all significant factors influencing soil moisture content. However, the interaction terms between these factors were found to be non-significant. A key outcome of this study was the development of predictive models for soil moisture content under different tillage conditions, namely No Tillage, Conservative Tillage, and Conventional Tillage. These models could be employed to forecast soil moisture content for specified levels of irrigation deficit percentage and NPK application rate under each tillage condition. The findings of this research provide valuable insights into the effects of irrigation deficit percentage, NPK application rate, and tillage on soil moisture content. These insights could be applied to inform agricultural practices in similar regions, ultimately contributing to improved crop yields and sustainable agricultural management
Assessment of Effect of Alummina Addition on the Refraractory Under Load (Rul) Property of Some Kaolin Clay Deposits in Nigeria
Get PDFThe impact of alumina addition on the Refractory Under Load (RUL) of kaolin clay deposits in Nigeria have been investigated. The samples deposit were collected from different sites of Ikpeshi Akoko Edo (IKAE) of Edo State, Kasadi Village in Kebbi State (KVK), Alasan in Osun State (AOS) and Badeggi in Niger State and were used as the principal raw material in the sample preparation while ball clay was used as the binder. The kaolin and ball clay were mixed in suitable proportion of 70:30 ratio in the production of the fire clay bricks. Particle size distributions and Refractory under load (RUL) of the samples were determined. Through RUL tests, samples without alumina exhibited varying subsidence behaviours at different temperatures. Samples from Kasadi (KVK) and Alaasan (AOS) showed the greatest improvement at 10% and 15% alumina levels, with lower subsidence and higher peak temperatures. With 10% and 15% alumina additions, respectively, the Kasadi sample reached maximal thermal stability with subsidence temperatures of 1475°C and 1516°C. Excellent refractory properties were likewise demonstrated by the Alaasan sample, but with less early expansion. On the other hand, the Ikpeshi (IKAE) sample underwent more overall deformation, suggesting a lower level of long-term thermal resistance, even if it was initially able to endure high temperatures. Results suggest alumina content influences the thermal stability and performance of kaolin clay, important for firebrick production and industrial applications. Practical tests confirmed the suitability of produced refractory bricks for industrial use, demonstrating comparable performance to standard refractory fire clay
Performance Evaluation and Optimization of a Canvas Belt Cowpea Thresher for Small-Scale Farming Applications
Get PDFThis study evaluates the performance of a canvas belt thresher designed specifically for cowpea, addressing post-harvest challenges in threshing efficiency, seed damage, and grain loss. Traditional threshers often lack precision for cowpea, leading to reduced yield and high labour demands. The constructed canvas belt thresher was tested at various drum speeds (200–1200 rpm) and moisture contents (10–14%) to determine its impact on threshing recovery, efficiency, cleaning ability, and seed integrity. Comparative performance was also assessed against a spike-tooth thresher, revealing the canvas belt thresher’s enhanced threshing efficiency (93.98%) and lower unthreshed grain percentage (6.02%) at optimal conditions. While the canvas belt thresher showed reduced throughput (91.33 kg/h) compared to the spike-tooth (181.89 kg/h), it minimized grain damage (3.83% vs. 11.54%) and achieved a higher threshing recovery rate (89.62%). Overall, the canvas belt thresher demonstrated effective threshing and cleaning for cowpea, although certain design refinements, such as covering the belt edges to reduce seed loss, could further enhance its efficiency and yield. This study highlights the potential of a canvas belt thresher for cowpea to support post-harvest processing, reduce losses, and improve yield quality in regions reliant on cowpea as a staple crop. Future research could investigate adjustments in belt configuration and speed control for further optimization
Adsorption Isotherms and Kinetics of Heavy Metals from Tannery Effluent Using Composite Agricultural Waste
Get PDFTannery wastewaters are very complex and characterized by high content of organic, inorganic and nitrogenous compounds which include heavy metals. In this study, the adsorption Isotherm and kinetics of a composite adsorbent produced from the chemical activation of groundnut shell and rice husk were utilized as agricultural waste in the removal of Pb, Cr and Cd from tannery effluent. The experimental data were fitted to Langmuir, Freundlinch and Temkin isotherm while the kinetics were also studied using Pseudo-First-Order and Pseudo-Second-Order kinetic models. The result revealed that Langmuir isotherm model showed excellent fit to the experimental data for all the heavy metal adsorption onto Groundnut shell activated carbon (GR-AC). This can be seen from the high correlation coefficients R2. The Langmuir monolayer adsorption capacity (qm) value was found to be 9.81 mg/g (Pb), 5.72 mg/g (Cr) and 4.25 mg/g (Cd) respectively. The equilibrium adsorption capacity (qe) values calculated from the Second Order kinetics model agree well with the experimental values for Pb and Cd. In addition, the First Order Kinetic rate constant decreased with increase in initial metal ion concentration. The excellent correlation between the calculated qe and experimental qe values and higher regression coefficient R2 shows clearly that the adsorption of these heavy metals onto GR-AC followed Pseudo-Second-Order kinetic model. Therefore, groundnut shell and rice husk can effectively be utilized as agricultural waste to produce a composite adsorbent to remove Pb, Cr and Cd from tannery effluent